Improving the efficiency of ITO/nc-TiO(2)/CdS/P3HT:PCBM/PEDOT:PSS/Ag inverted solar cells by sensitizing TiO(2) nanocrystalline film with chemical bath-deposited CdS quantum dots

An improvement in the power conversion efficiency (PCE) of the inverted organic solar cell (ITO/nc-TiO(2)/P3HT:PCBM/PEDOT:PSS/Ag) is realized by depositing CdS quantum dots (QDs) on a nanocrystalline TiO(2) (nc-TiO(2)) film as a light absorption material and an electron-selective material. The CdS QDs were deposited via a chemical bath deposition (CBD) method. Our results show that the best PCE of 3.37% for the ITO/nc-TiO(2)/CdS/P3HT:PCBM/PEDOT:PSS/Ag cell is about 1.13 times that (2.98%) of the cell without CdS QDs (i.e., ITO/nc-TiO(2)/P3HT:PCBM/PEDOT:PSS/Ag). The improved PCE can be mainly attributed to the increased light absorption and the reduced recombination of charge carriers from the TiO(2) to the P3HT:PCBM film due to the introduced CdS QDs.